The wind generator is an apparatus in which a rotor head having windmill blades receives wind power and rotates, and electricity is generated by a power generator that is driven by accelerating this rotation by a speed-up gear.
The rotor head is mounted on an end of a nacelle that is disposed on a windmill tower (“tower”, hereinafter) and is capable of yaw-slewing, and the rotor head is supported such that the rotor head can rotate around a substantially horizontal lateral rotation axis.
Generally, towers for the windmill employ a steel monopole structure using a cylindrical shell in many cases, and a base plate provided on a lower end of a shell plate is fixed to a base of a reinforced concrete through anchor bolts.
Since such a wind generator includes an electric device such as a converter, in order to continue the stable operation, it is necessary to cool the electric device that is a heating element.
In order to cool the heating element such as the electric device, some of the conventional wind generators include a cooling device that circulates a cooling medium to cool the heating element.
As disclosed in patent literature 1 for example, the cooling device includes a heat exchanger disposed outside the tower, and a cooling medium introduced into the heat exchanger exchanges heat with respect to outside air, thereby cooling the heating element.